A cohort of 551 persons over age 60 with isolated systolic hypertension was recruited in 1981 and 1982 for a pilot study to test the feasibility of a full scale trial of the effects of stepped care drug treatment on health. Funding for the pilot study will end in June 1984; although the initial goal has been achieved, several important new research questions have arisen, and there is the need for completing all the work that has begun. The proposed research has the following objectives: 1. To test the safety and efficacy of low dose diuretic treatment, with and without beta blocking drugs, in isolated systolic hypertension in the elderly. Specifically, what proportion of patients can be controlled with 12.5 mg of chorthalidone daily, and does the addition of metoprolol to chlorthalidone alter the level of blood pressure control or the prevalence of side effects? 2. To study for two added years a cohort of elderly patients with isolated systolic hypertension who have been followed closely for two years, receiving either stepped care treatment or placebo, in order to a) validate and extend the incidence estimates for morbidity; b) improve the methods for adverse event monitoring; c) extend the incidence estimates for behavioral dysfunction; and d) complete the development and testing of the distributed data system. 3. To analyze and report the results from the Systolic Hypertension in the Elderly Program pilot study, publishing the scientific findings and the methodological advances in clinical trial technology.